Malware
In the 1980s the first PC viruses emerged. Boot sector viruses invaded the floppy disk. Almost immediately the first anti-virus products emerged. Doctor Solomon's Anti-Virus Toolkit was one of the first. Alan Solomon had, in fact, created standalone anti-virus tools for some time as S&S Enterprises. Back in the early 90s I was a beta tester for this product and my then boss was involved in selling it. The PC industry was pretty small and I had a small part in the development in the UK anti-virus industry. Consolidation led to the product being sold and we all moved on. The key point was that the business opening was that DOS and Windows wasn't very secure. This didn't really matter too much when computers weren't networked to the extent they are today. Two decades later Microsoft have had their Trustworthy Computing programme which brought about fundamental changes in the Windows platform and the modern BIOS . Which brings me to the question someone recen